Field of the Invention
The present invention relates to a damper device for a vehicle drive shaft. More particularly, the present invention relates to a dynamic damper which is provided with a clamping band that is improved to correct damping frequency by changing rigidity of the dynamic damper fixed to a drive shaft in accordance with a change in temperature in order to maintain an effect of the damper that reduces vibration and noise despite a change in temperature.
Description of Related Art
A drive shaft is used to transmit power generated by a vehicle engine to a wheel. Vibration is generated by the drive shaft applied to a medium-sized or small-sized vehicle when the drive shaft is rotated at a high speed. In this drive shaft, resonant frequency of a long shaft is 120 to 130 Hz, and resonant frequency of a short shaft is 260 to 300 Hz. In general, the resonant frequency matches with a portion vulnerable to acceleration noise and vibration of the vehicle, which mainly causes deterioration in noise, vibration and harshness (NVH) performance.
In order to solve the problem regarding the vibration, a dynamic damper, which is adapted to the resonant frequency, is mounted on the drive shaft to reduce vibration and noise.
However, control frequency of the dynamic damper applied to the drive shaft is sensitive to a temperature such that the control frequency is higher than target frequency in a cool state, and lower than target frequency in a hot state, and as a result, effects of reducing noise and vibration may be lowered or may deteriorate at the frequency with problems.
In order to solve the problem, as illustrated in FIG. 1, the prior art discloses a dynamic damper for a constant velocity joint, which is disposed on a drive shaft, the dynamic damper including a cylindrical main body 110 which is disposed on the drive shaft 1 and has a space therein; a first weight 130 which is disposed in the main body 110 in parallel with the drive shaft 1, a second weight 140 which is disposed on an inner circumferential surface of the main body 110 in a direction orthogonal to the drive shaft 1, and a filling material 120 which is stored in an internal space of the main body 110 to prevent the first and second weights 130 and 140 from being moved, in which the main body 110 includes a thermoplastic elastomer (TPE), and the filling material 120 includes a thermoplastic elastomer (TPE) having Shore hardness of 50 to 70 A.
The prior art discloses a damper which may change and adjust frequency properties of the damper by allowing a contact area between a fixing member and a mass member to be changeable.
As another example, prior art discloses a dynamic damper in which a metallic member is coupled to a rubber elastic member.
The dynamic damper in the related (prior) art uses rubber made of thermoplastic elastomer to prevent properties of the rubber from being greatly changed due to a change in temperature, but in a case in which the dynamic damper is made of this rubber material, damping force is relatively low, and effects of reducing vibration and noise deteriorate. Further, a number of improved methods of allowing the mass member of the damper to mainly correspond to a change in temperature have been proposed and result in significant effects, but because of various changes in temperature in view of the four seasons, a problem caused by a change in rigidity of the damper, which is caused by a change in coupling force of the damper to the drive shaft by a band that typically couples the damper to the drive shaft, cannot be solved.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.